ByHarold Heckle and Joseph Wilson, Associated PressSeptember 27, 2015

Catalonian independence supporters react in Barcelona, Spain, Sunday Sept. 27, 2015. Voters in Catalonia participated in an election Sunday that could propel the northeastern region toward independence from the rest of Spain or quell secessionism for years. Secessionists have long pushed for an independence referendum, but Spain's central government has not allowed one, arguing it would be unconstitutional because only it can call such a vote.

BARCELONA — An exit poll predicted on Sunday that pro-independence parties in Spain's Catalonia region were likely to win a majority of seats in the regional parliamentary election, but it's unclear whether they would be able to come together to push for a plan to secede from Spain.

The exit poll by Catalonia's TV3 channel showed the "Together for Yes" group of secessionists winning 63-66 seats in the 135-member parliament. That's short of the 68 seats they needed for a majority to push forward their plan to make Catalonia independent from Spain by 2017.

But the radical left pro-independence Popular Unity Candidacy party was projected to win 11 to 13 seats in the parliament, which represents the northeastern region of 7.5 million people bordering France that is responsible for nearly a fifth of Spain's economic output.

The two parties could join forces after negotiations but the Popular Unity Candidacy, known as CUP, has insisted that it will only push for independence if secessionist parties win a majority of more than 50 percent of the popular vote.

The exit poll showed the pro-independence parties falling just short of that level, because of a quirk in Spanish election law that gives a higher proportion of legislative seats to rural areas with fewer voters. CUP leaders have also declared that they want an immediate declaration of independence rather than the 18-month secession roadmap favored by the "Yes" bloc.

Polls have closed in Catalonia and votes were being tallied. Final results were expected late Sunday or early Monday.

Secessionists have long pushed for an independence referendum, but Spain's central government refused to allow it – saying such a vote would be unconstitutional. So the pro-independence parties pitched the vote for regional parliamentary seats as a de facto plebiscite.

The central government of Prime Minister Mariano Rajoy says it will use all legal means to prevent Catalonia from breaking away, an exit European leaders warn would include ejection from the European Union.

Spain's government has also said it is concerned that if Catalonia tries to break free it would disrupt the fragile signs of economic recovery for the country that has endured unemployment of over 22 percent for several years.

Catalans from both sides of the independence divide are fiercely proud of their Catalan language, which is spoken along with Spanish and was suppressed under three decades of Gen. Francisco Franco's dictatorship.

Many Catalans are also angry because they say their industrialized region, which represents nearly a fifth of Spain's economic output, pays too much in taxes and receives less than its fair share of government investment.

Jordi Perez, a 50-year-old civil servant said he voted for "Together for Yes" because he feels Spain has historically disparaged Catalan culture and its language.

"I have wanted independence ever since I was young," Perez said after voting in Barcelona. "During three centuries they have robbed us of our culture. We have reached the moment that the Catalan people say 'enough is enough.'"

While the pro-independence camp has organized massive rallies of hundreds of thousands in recent years, those in favor of remaining a part of Spain have kept a low profile.

School teacher Sandra Guerrero, 30, said that these elections motivated her to vote for the first time – for the anti-independence Citizens party.

"I feel part of Spain. I am proud to be Catalan, but also to be Spanish," she said. "I had never voted before because I was disillusioned with politics. But this time I have because these are important elections."

Harold Heckle reported from Madrid. Alan Clendenning contributed to this report from Madrid.